Add density code for DAT-72, and notes on DAT-160.

As it turns out, the density code for DAT-160 (0x48) is the same
as for SDLT220.  Since the SDLT values are already in the table,
we will leave them in place.

Thanks to Harald Schmalzbauer for confirming the DAT-72 density code.

lib/libmt/mtlib.c:
	Add DAT-72 density code, and commented out DAT-160 density
	code.  Explain why DAT-160 is commented out.  Add notes
	explaining where the bpi values for these formats came from.

usr.bin/mt/mt.1:
	Add DAT-72 density code, and add a note explaining that
	the SDLTTapeI(110) density code (0x48) is the same as
	DAT-160.

Sponsored by:	Spectra Logic
MFC after:	3 weeks

1 files changed, 17 insertions, 0 deletions

diff --git a/lib/libmt/mtlib.c b/lib/libmt/mtlib.c
index ad73381..f6acba2 100644
--- a/lib/libmt/mtlib.c
+++ b/lib/libmt/mtlib.c
@@ -568,6 +568,15 @@ static struct densities {
 	 *
 	 * IBM 3592 definitions obtained from second edition of the IBM
 	 * System Storage Tape Drive 3592 SCSI Reference (May 25, 2012).
+	 *
+	 * DAT-72 and DAT-160 bpi values taken from "HP StorageWorks DAT160
+	 * tape drive white paper", dated June 2007.
+	 *
+	 * DAT-160 / SDLT220 density code (0x48) conflict information
+	 * found here:
+	 *
+	 * http://h20564.www2.hp.com/hpsc/doc/public/display?docId=emr_na-c01065117&sp4ts.oid=429311
+ 	 * (Document ID c01065117)
 	 */
 	/*Num.  bpmm    bpi     Reference     */
 	{ 0x1,	32,	800,	"X3.22-1983" },
@@ -613,6 +622,14 @@ static struct densities {
 	{ 0x42, 7398,   187909, "LTO-2" },
 	{ 0x44, 9638,   244805, "LTO-3" }, 
 	{ 0x46, 12725,  323215, "LTO-4" }, 
+	{ 0x47, 6417,   163000, "DAT-72" },
+	/*
+	 * XXX KDM note that 0x48 is also the density code for DAT-160.
+	 * For some reason they used overlapping density codes.
+	 */
+#if 0
+	{ 0x48, 6870,   174500, "DAT-160" },
+#endif
 	{ 0x48, 5236,   133000, "SDLTapeI(110)" },
 	{ 0x49, 7598,   193000, "SDLTapeI(160)" },
 	{ 0x4a,     0,       0, "T10000A" },